All four were taken to hospitals in the Italian port of Livorno after the crew of the MSC Orchestra reported the illnesses, the ministry said. More than 2,800 doses of the antibiotics ciprofloxacin and rifampicin were issued for passengers, and the ministry said passengers who have disembarked in the past week should take similar precautions.

The 294-meter (965-foot), 2,500-passenger Orchestra is currently in the French port of Villefranche sur Mer, on the outskirts of Nice, and the ministry said Italian authorities have notified their French counterparts. MSC, the passenger arm of Italy's Mediterranean Shipping Company, said it was doing "everything necessary to safeguard the health of its guests and all the crew members."

The crew members were diagnosed with meningococcal meningitis, which attacks the lining of the brain and the spinal cord. The disease is passed by close contact with respiratory secretions or saliva, according to the U.S. Centers for Disease Control.

"The strand was found in the crew that worked in the kitchen and that, therefore, they should not have had continuous and close contact with passengers," the Health Ministry noted. Two of the four cases were identified as Meningitis C.

The cases involve a different disease than the outbreak of fungal meningitis now being seen in the United States. Eight people have died after being injected with steroids contaminated by a fungus, the CDC reported Monday.